<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS选择器-并集选择器</title>
    <style>
        /* 并集选择器 */
        p,div,#sp,.h{
            color: navy;
        }
    </style>
</head>
<body>
    <p>文字</p>
    <div>文字</div>
    <span id="sp">文字</span>
    <h3 class="h">文字</h3>
</body>
</html>